Circuit control mechanism for mechanical refrigerating apparatus



Sept. 29, 1931. F. R. ERBACH 1,824,774

CIRCUIT CONTROL MECHANISM FOR MECHANICAL REFRIGERATING APPARATUS FiledDec. 19, 1927 1:: \fvw v INVENTOR. Eedez'ickEErbdch A TTORNE Y5.

Patented $6 ,029, 1931- UNITED STATES (PATENT OFFICE.

FREDERICK R. war or DETROIT, MICHIGAN, ASSIGNOR To KEtvINAToR conno-RATION, OF DETROIT, MICHIGAN,

A CORPORATION OF MICHIGAN CIRCUIT CONTROL MECHANISM FOR MECHANICALREFRIGEBATING APPARATUS Application filed December 19, 1927. Serial No.241,072.

Mechanical refrigerating apparatus now associated with refrigeratorsoperate periodically to automatically "maintain a predeter- -mined rangeof temperature by means of a 5 temperature responsive mechanism whichmakes and breaks the electrical circuit leading from a source ofelectrical supply tothe motor for driving a compressor. A cooling unitis arranged in communication with the chamber to becooled andcompartments for receiving trays containing liquids to be frozenareusually arranged interiorly of the cooling unit. With suchintermittently operating apparatus, a considerable time is re- 1 quiredto freeze the liquids in the trays when thetemper ature range maintainedin the refrigerator is above freezing, and under some circumstances itis desirable to procure quicker freezing than that resulting fromapparas tus set to automatically maintain a temperature range abovefreezing.

An object of my invention is to procure continuous operation ofautomatically actuated mechanical refrigerating apparatus, normallyoperating intermittently, in order to decrease the time for freezingliquidswithin a refrigerator.

Afurther object of my invention is to asso-- ciate mechanism withautomatic mechanical 3o. refrigerating apparatus, normally operatingintermittently, which can be manually moved into a position to causecontinuousoperation of the refrigerating apparatus,-and which isautomatically returned to its original position when a predeterminedtemperature is effected in therefrigerator by the continuous operationofthe apparatus.

Another object of my invention is to utilize an air circulation controldamper in a refrigerator for effecting operation of a switch mechanismassociated in the electri'calcircuit extending from a source ofelectrical supply to a driving motor. T I

' Other objects of my invention moraor less incidental orancillary tothe foregoing will appear in the followingdescription which" sets forth,in connection with the drawings I accompanying and forming a. part ofthis specification, a preferred embodiment of the. invention. s D

I R-EISSUED n the accompanying rawings Figure 1 is a front elevation ofa refrigerator cabinet having a mechanical cooling unit in-onecompartment and my control device associated with a flue therein throughwhich the air circulates, the doors of the cabinet being removed; and

Figure 2 is an elevational view of my inve'nt1on, partiallydiagrammatic, associated with the adjacent portion of the refrigeratorcabinet, which is shown in section.

Referring now to the drawings by characters of reference, 10 illustratesa refrigerator cabinethaving an interior chamber .divided by verticalpartition 11 anda horizon.- tal partition-l2 providing food storagechambers 13' and 14 and a chamber 15 for the reception of the heattransfer unit 16 of mechanical refrigerating apparatus. The mechanicalrefrigerating apparatus can be of the compressor-condenser-evaporatortype having an electrical circuit 17 extending through a motor 18 whichoperates the compressor (not shown), the circuit being automaticallybroken and established by a thermostatically actuated switch mechanism18. The partition 12 is provided with a flue 19 and the partition 11 isprovided with upper and lower flues 20 and 21. the flues allowing acircula- I tion of air through the chambers. The structure so fardescribed is so generally known and, understood that a more completedisclosure and further description of the details is not thought to benecessary to understand my invention which is associated therewith, andwhich Iiwill now describe.

The automatic control of refrigerating apparatus, in maintaining aredetermined temperature range above freezing in the food storagecompartments, will start and stop several times before water or fluidswill be frozen after insertion into the open chambers in the coolingunit, and therefore an objectionable length of time is required for thefreezing operation. In order to decrease the freezing time normallyrequired by automatically operated mechanical refrigerating apparatus, Ihave provided mechanism for causing the refrigeratingi'apparatus tooperate continuously until a predetermined low temperature V a bracket2&rvlhi m s ttachl illql depending.

is obtained in the cooling chamber which mechanism is arranged to beassociated with an air circulation control damper 22. This mechanism isarranged in a circuit parallel to that of the thermostat 18 andconsequently is not affected by the operation of that element. Areinforcing collar 23 is secured to the partition 12 adjacent the flueopening 19 therein, and such member is provided with a bearing portion24 and a surrounding opening which permits air to circulate from thechamber 15 to the chamber 14., The damper 22 is preferably arrangedwithin the chamber 15 and is of such size that it can close the open ingin the member 23 to shut off air circulation between the chambers 15 and14. The damper is provided with a stem portion 25 which extends throughthe bearing 24 and into the chamber 14, the stem terminating in ahand-leportion 26. A coil spring 27 surrounds the stem portion ofthe'damper structure intermediate the closure member 22 and the bearingmember 24. Such spring normally maintains the closure member in openposition with respect to the fiue19.

A motor control device is arranged to be.

actuated byv the movement of the damper, and the mechanical portionthereof is carried by portion 29 of the member 23. A switch base i 30,formed of insulating material, is secured from in spaced and parallelrelation toward the stem portion 25 of the damper. The damper stem isprovided with a projecting portion 33 which is arranged to engage andactuate the upper contact arm and move it into engagement with the lowercontact'arm When the damper is pulled downwardly to close the flueopening 19. It will thus be seen that when the damper is moved to closedposition, the top switch arm 32 will be forced thereby into engagementwith the other switch arm, thus establishing an electrical circuitthrough the motor 18 which will cause continuousoperation ofv therefrigerating apparatus until such time as the damper is L movedto openposition.

i the upper end of the lever 36 when the damper ismoved to closedposition. The lever is The damper stem is provided with a notch 34 whichis engaged by a pawl35 formed at pivoted adjacent its lower end betweenthe bracket extensions 37, and coil springs 38 and 39 extend betweenandare secured to the ends of the lever 36 and the bracket 28, the ends ofthe springs extending through the bracket 28 and being threaded toreceive securing nuts 40. The relative tension of the springs 38 and 39and the mounting of the lever 36 is such that the pawl 35 willautomatically move into the notch 34 when the notch is moved to aposition opposite the pawl, in which position the damper Will be in aposition to close the flue opening 19. It will be seen that the stemportion of the damper extends into the chamber 14, so that the handleportion 26 can bereadily grasped when the refrigerator door is open inorder to move the damper downwardly into a position in which it willclose the flue opening in the partition 12. When the damper is manuallymoved to closed position, the pawl 35 engages the notch 34 in the damperstem and automatically maintains the damper in closed position untilreleased. A thermostat device is associated with the lever 36 f0rreleasing the pawl from the notch in the damper arm when a predeterminedlow temperature has been reached within the chamber-15.- This deviceconsists of a bellows member 41 which is closed at one end and engageswith an extension of the lever 36. The bellows is secured to'the bracket28 and a condu it 42 communicating leads from the bellows ll dth housing43. T Itwillb e understood tha a suitable expansible fluid is placedWithin the bellows-and the communicating conduit 42 and housing 43 whichwill be affected by the temperature in the chamber 15 causing thebellows 41 to contract and expand, so that when a predetermined freezingtemperature hasbeen reached in the chamber 15, the movement ofthebellows toward the bracket 28 moving the lever 36 therewith releases thepawl 35 from the notch 34 in the damper stem allowing the switch arms toseparate as the damperstem is moved by the spring 27 to open position.

It will be understood that when a freezing temperature is produced inthe chamber 15 and the air is permitted to circulate, then food storedwithin the chambers 13 and 14 will befrozen and spoiled. By arrangingthe damper so that it cooperates with the circuitcontrol mechanism, itwill be seen that the damper will be closed when the circuit isestablished to produce a lower temperature in the compartment than ispermitted when under the control of thermostat 18, and in this mannercirculation of'air when the lower temperature for freezing is'desiredwill be prevented. Under such circumstances there will be very littlelikelihood of the air within the, food storage chambers becoming coldenough to freeze and spoil the food stored therein. -The thermostatbellows can be adjusted to release the pawl so that the desiredtemperature in the chamber 15 can be obtained by the relative adjustmentof the tension of the springs 39.

Although I have illustrated but one form of my invention and havedescribed in detail but a single application thereof, it will beapparent to those skilled in the art that it is not so limited but thatvarious modifications and changes may be made therein without departingfrom the spirit of my invention or the scope of the appended claims.

What I claim is:

1. In combination with refrigerating apparatus having electricalconnections for establishing a circuit between a driving motor and asource of electrical supply, an automatically operated switch mechanismfor establishing and breaking said circuit upon predeterminedtemperature conditions, and a second switch mechanism for controllingsaid circuit independently of said automatically operated switchmechanism, said last mentioned switch mechanism being manually operable-to establish said circuit and including means for automaticallybreaking said circuit under a predetermined temperature condition.

2. In combination with refrigerating apparatus having electricalconnections for establishing a circuit between a driving motor and asource of electrical supply, an automatically operated switch mechanismfor establishing and breaking said circuit upon predeterminedtemperature conditions, a manually operable mechanism for establishingsaid circuit independently of said switch mechanism, and automatic meansfor breaking the circuit established by said manually operable means. Y

3. In combination with refrigerating apparatus having electricalconnections for establishing a circuit between a driving motor and asource. of electrical supply, automatically operated switch mechanismresponsive to close and break said circuit upon predeterminedtemperature conditions, and a second switch mechanism adapted to closeand break said circuit independently of said first switch mechanism,said secondswitch being manually operable to close the circuit andautomatically operated to break the circuit upon a lower temperaturethan eflected by said first mentioned switch mechanism.

4. Control mechanism for an electrical circuit associated withrefrigerating apparatus, comprising in combination a switch mechanism insaid circuit, an air circulation control damper for causing actuation ofsaid switch mechanism to make and break said comprising the combinationof a switch, an air clrculation damper arranged to actuate said switch,said damper being manually op between the compartments, of means forpreventing such circulation of air and for initiating the operation ofthe condensing unit simultaneously, and means for rendering the lastmentioned means inoperative when the temperature of the freezingcompartment reaches a predetermined sub-normal value.

In testimony whereofI hereunto aflix my signature.

FREDERICK R. ERBACH.

circuit, said damper being manually actuated to prevent air circulationand to move said switch to close said circuit, said damperbeing-automatically moved to permit air circulationand to permit saidswitch to move position, and a thermostat connected to allow automaticmovement of said damper.

5. Control mechanism for an electrical circuit associated withrefrigerating apparatus

